PARTITION_NAME: p0 SUBPARTITION_NAME: NULL PARTITION_ORDINAL_POSITION: 1 SUBPARTITION_ORDINAL_POSITION: NULL PARTITION_METHOD: RANGE SUBPARTITION_METHOD: NULL PARTITION_EXPRESSION: id SUBPARTITION_EXPRESSION: NULL PARTITION_DESCRIPTION: 10 TABLE_ROWS: 2 AVG_ROW_LENGTH: 8192 DATA_LENGTH: 16384 MAX_DATA...
(partition p1 values less than (1000)); —-不会丢失数据 重新定义hash分区表: Alter table emp partition by hash(salary)partitions7; —-不会丢失数据 重新定义range分区表: Alter table emp partitionbyrange(salary) ( partition p1 values less than (2000), partition p2 values less than (4000) );...
select partition_name part,partition_expression expr,partition_description descr,table_rows from information_schema.partitions where table_schema = schema() and table_name='t_send_message_send'; 1 2、查询表分区数据 select * from t_send_message_send partition(p2020); (21条消息) Mysql已有亿级数据...
上述示例创建了一个名为`my_table`的表,并使用`id`字段进行常规HASH分区。根据指定的4个分区,MySQL会根据`id`字段的哈希结果将数据均匀地存储到这四个分区中。 验证分区 我们使用如下SQL验证4个分区情况: SELECT PARTITION_NAME, PARTITION_METHOD, PARTITION_EXPRESSION, PARTITION_DESCRIPTION, TABLE_ROWS FROM info...
PARTITION_METHOD:分区的方法,例如RANGE、LIST、HASH等。 SUBPARTITION_METHOD:子分区的方法,如果表有子分区的话。 PARTITION_EXPRESSION:分区的表达式。 SUBPARTITION_EXPRESSION:子分区的表达式,如果表有子分区的话。 PARTITION_DESCRIPTION:分区的描述信息。 TABLE_ROWS:分区内的行数。
PARTITION_EXPRESSION, PARTITION_DESCRIPTION, PARTITION_ORDINAL_POSITIONFROMINFORMATION_SCHEMA.PARTITIONSWHERETABLE_NAME='t_partition_by_range';---END RANGE--- 分区存储信息结果: 如上表,理论与实际结合分析: 把id < 5的4个实体(wangchao、suntao、...
`PARTITION_EXPRESSION` longtext, `SUBPARTITION_EXPRESSION` longtext, `PARTITION_DESCRIPTION` longtext, `TABLE_ROWS` bigint(21) unsigned NOT NULL DEFAULT '0', `AVG_ROW_LENGTH` bigint(21) unsigned NOT NULL DEFAULT '0', `DATA_LENGTH` bigint(21) unsigned NOT NULL DEFAULT '0', ...
倒数3行-partition active storage engne null gpl 如果有就支持,下一步 2、MySQL分区表的特点 在逻辑上为一个表,在物理上存储在多个文件中 3、查询mysql源文件存放位置 SHOW VARIABLES LIKE '%datadir%'; 4、查看分区: SELECT PARTITION_NAME,PARTITION_METHOD,PARTITION_EXPRESSION,PARTITION_DESCRIPTION, ...
PARTITION_NAME: p0 SUBPARTITION_NAME: p0sp0 PARTITION_ORDINAL_POSITION: 1 SUBPARTITION_ORDINAL_POSITION: 1 PARTITION_METHOD: RANGE SUBPARTITION_METHOD: HASH PARTITION_EXPRESSION: year(b) SUBPARTITION_EXPRESSION: TO_DAYS(b) PARTITION_DESCRIPTION: 1990 ...
than (10, 35),partition p05 values less than (10, maxvalue),partition p06 values less than (maxvalue, maxvalue),);insert into rc3(a, b) values(1, 10);select (1, 10) < (10, 10) from dual;-- 根据结果存放到p02分区上了selectpartition_name,partition_expression,partition_description,...